Instruction manual

13. Glossary

• Dual Stream: Dual stream is a technology used to record high resolution video locally

while transmitting a lower resolution stream over the network. The two streams are

generated by the DVR, with the main stream having a maximum resolution of 4CIF and

the sub-stream having a maximum resolution of CIF.

• DVR: Acronym for Digital Video Recorder. A DVR is device that is able to accept

video signals from analogue cameras, compress the signal and store it on its hard drives.

• HDD: Acronym for Hard Disk Drive. A storage medium which stores digitally encoded

data on magnetic surfaces.

• DHCP: Dynamic Host Configuration Protocol (DHCP) is a network application

protocol used by devices (DHCP clients) to obtain configuration information for

operation in an Internet Protocol network automatically.

• HTTP: Acronym for Hypertext Transfer Protocol. A protocol to transfer hypertext

request and information between servers and browsers over a network.

• DDNS: Dynamic DNS is a method, protocol, or network service that provides the

capability for a networked device, such as a router or computer system using the Internet

Protocol Suite, to notify a domain name server to change, in real time (ad-hoc) the active

DNS configuration of its configured hostnames, addresses or other information stored in

DNS.

• Hybrid DVR: A hybrid DVR is a combination of a DVR and NVR.

• NTP: Acronym for Network Time Protocol. A protocol designed to synchronise the

clocks of computers over a network.

• NTSC: Acronym for National Television System Committee. NTSC is an analogue

television standard used in such countries as the United States and Japan. Each frame of

an NTSC signal contains 525 scan lines at 60Hz.

• NVR: Acronym for Network Video Recorder. An NVR can be a PC-based or

embedded system used for centralised management and storage for IP cameras, IP Domes

and other DVRs.

• PAL: Acronym for Phase Alternating Line. PAL is also another video standard used in

broadcast televisions systems in the U.K. PAL signal contains 625 scan lines at 50Hz.

• PTZ: Acronym for Pan, Tilt, Zoom. PTZ cameras are motor driven systems that allow

the camera to pan left and right, tilt up and down and zoom in and out.

• USB: Acronym for Universal Serial Bus. USB is a plug-and-play serial bus standard to

interface devices to a host computer.

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